Adaptive Dissemination of Data in Time-Critical Asymmetric Communication Environments

Abstract

The proliferation of new data-intensive applications in asymmetric communication environments has led to an increasing interest in the development of push-based techniques, in which the information is broadcast to a large population of clients in order to achieve the most efficient use of the limited server and communication resources. It is important to note that quite often the data that is broadcast is time-critical in nature. Most of the related current research focuses on a pure push-based approach (Broadcast Disks model), where the transmission of data is done without allowing explicit requests from the users. More recently, some bidirectional models incorporating a low-capacity uplink channel have been proposed in order to increase the functionality of the Broadcast Disks model. However, the impact of integration of the uplink channel has been investigated using only static client profiles or ignoring the existence of time-sensitive data. None of the existing models integrates all the characteristics needed to perform effectively in a real-world, dynamic time-critical asymmetric communication environment. In this paper we present an adaptive data dissemination model and the associated on-line scheduling algorithms. These improve the functionality and performance of bidirectional broadcast models, maximizing the total number of satisfied users in asymmetric communication environments with dynamic client profiles and time requirements (e.g., mobile systems). This is achieved by means of dynamic adaptation of the broadcast program to the needs of the users, taking into account the bandwidth constraints inherent in asymmetric communication environments and the deadline requirements of the user requests. Performance is evaluated by simulation of a real-time asymmetric communication environment.

Scheduling real-time requests in on-demand data broadcast environments

“…Xuan et al (1997) showed that on-demand broadcast by using EDF (Earliest Deadline First) achieves good performance. In Fernandez and Ramamritham (2004), an adaptive approach is suggested to allocate bandwidth for periodic and on-demand broadcast in time-critical asymmetric communication environments. In Lam et al (2000), Absolute Validity Interval (AVI) was introduced to capture the temporal constraints of data items.…”

Disseminating data with time constraint based on multichannel over ubiquitous computing environments

“…There has been some research work to consider disseminating for mobile real-time systems [17]. A transfer protocol for organizing air disks for real-time applications, called Adaptive Information Dispersal Algorithm (AIDA), is presented in [8].…”

Real time stochastic scheduling in broadcast systems with decentralized data storage

“…A hybrid broadcasting approach is proposed by Fernandez and Ramamritham (2004) to cater to the deadline requirement. Wu and Lee consider constraints such as request deadlines and temporal data validity while proposing the RDDS algorithm (Wu and Lee 2005).…”